May 29, 2009

Ancient mtDNA and craniometric evolution of Amerindians

This paper shows that while the mtDNA gene pool of Amerindians did not undergo substantial change since the Holocene (haplogroups B, C, D were detected in the ancient samples, all of them common today), their cranial morphology changed from a more generalized to a more Mongoloid pattern.

In my opinion, the fact that Amerindians evolved in a Mongoloid direction may suggest one of three things:

proto-Mongoloid traits were present as tendencies in the founding population, and they evolved in parallel in the Americas and in East Asia

proto-Mongoloid traits were absent in the founding population, and they evolved independently in the Americas

proto-Mongoloid traits were absent in the founding population, but they were added by limited gene flow from Asia

Even in Asia itself, except for isolated finds in Siberia, the first full-blown Mongoloids emerge in the Holocene. The Mongoloid type even spread to the south of the continent, which was formerly occupied by populations more similar to Australo-Melanesians.

Why the type became so successful remains to be seen; adaptive explanations for a rounder skull, flatter face, and heavy eyelids have been proposed as responses to extreme arctic cold, but why would similar phenotypes be selected for in regions of less extreme climate?

Sexual selection might play a role, although it would be difficult to establish over such a large area.

My guess is that various aspects of the Mongoloid pattern existed in low frequency or as isolated tendencies across East Eurasia and America. As populations grew during the Holocene, these traits spread in a wider range. Naturally, in the periphery, their blending was incomplete, with different quasi-Mongoloid types emerging there, e.g., prominent-nosed, round-headed Amerindians vs. flat-nosed, long-headed Proto-Uralics.

Thus, ancestral Amerindians either already had, or later received -by limited gene flow- a set of Mongoloid traits from Asia, which were selected for the same reasons as they did in Asia, but the "bottleneck" of the Bering did not allow them to receive the full package of traits.

PLoS ONE doi:10.1371/journal.pone.0005746

Discrepancy between Cranial and DNA Data of Early Americans: Implications for American Peopling

S. Ivan Perez et al.

Abstract

Currently, one of the major debates about the American peopling focuses on the number of populations that originated the biological diversity found in the continent during the Holocene. The studies of craniometric variation in American human remains dating from that period have shown morphological differences between the earliest settlers of the continent and some of the later Amerindian populations. This led some investigators to suggest that these groups—known as Paleomericans and Amerindians respectively—may have arisen from two biologically different populations. On the other hand, most DNA studies performed over extant and ancient populations suggest a single migration of a population from Northeast Asia. Comparing craniometric and mtDNA data of diachronic samples from East Central Argentina dated from 8,000 to 400 years BP, we show here that even when the oldest individuals display traits attributable to Paleoamerican crania, they present the same mtDNA haplogroups as later populations with Amerindian morphology. A possible explanation for these results could be that the craniofacial differentiation was a local phenomenon resulting from random (i.e. genetic drift) and non-random factors (e.g. selection and plasticity). Local processes of morphological differentiation in America are a probable scenario if we take into consideration the rapid peopling and the great ecological diversity of this continent; nevertheless we will discuss alternative explanations as well.

58 comments:

Mongoloids are a very diverse kind craniometrically speaking. But they are genetically relatively homogeneous (Amerindians are different from the rest mainly because of bottlenecks, but by origin they are from the same stock). This plus the archaeological and ancient DNA evidence suggest strongly that their current craniometric variation is the result of very late events (e.g., Neolithic population explosion).

I would further add that Beringia and coastal north Asia likely had two distinct cultures and populations, based on sustenance: large game hunters in the plains, and coastal dwellers (fishing, seal and whale hunting). Comparing with European body types and present-day Inuits, one could imagine that cold-climate skull and body adaptations were different between these two - and they had 20,000 years or so time to form, while MtDNA groups were long set. If, as likely, representatives of both groups entered the Americas, that could easily make for a fragile situation where over 10,000 years or so it would depend very much on the climate and sustenance advantages, which body type or which parts of the mosaic would "win out" - or better, become more prevalent. And with the demise of big game in North America, there is at least one clear reason for a sudden population shift. Another one, like in the rest of the world, is the advent of agriculture.

"The Mongoloid type even spread to the south of the continent, which was formerly occupied by populations more similar to Australo-Melanesians".

Certainly in that case the change is accepted to have been caused by immigration, rather than evolution 'in a Mongoloid direction'.

I suspect that in the case of America option 3 is the likely one: 'proto-Mongoloid traits were absent in the founding population, but they were added by limited gene flow from Asia'. Especially because of the comment: 'haplogroups B, C, D were detected in the ancient samples'. What about A, and X?

The extent of haplogroup A is very limited among East Asians (except the Amerindian-like Chukchi). Haplogroup X is almost nonexistent among East Asians, while it can be found in relatively high rates among East Europeans and Middle Easterners, with the highest rate among Druze (26%). So your scenario is very implausible.

Mongoloids can't have evolved in Beringia. If they did, their spread into the Americas could be explained (as that is the only "entry point"), but how could their spread and dominance over Asia be explained?

Moreover, we know of the existence of Mongoloid traits in Siberia from the Upper Paleolithic, in sites well to the west and south of Beringia, in sites like Mal'ta and Afontova Gora II.

that mtDNA A was associated with Y-hap C3. in spite of some disagreement Y-hap C3 has certainly been claimed as a later immigrant to America, possibly associated with the Na-Dene group of languages in the northwest of North America. In fact Mongoloid features appear to be associated with two other Y-chromosomes: C1 and C2.

That the relationship is not simple, however, is demonstrated at the southern end of the C Y-hap cline. Most Australian Aborigines have Y-hap C4. East Asian? Many see some sort of similarity between Australian Aborigines and the Ainu however.

Perhaps the C Y-chromosome has simply spread through variuos pre-existing populations. However we can discern a connection between an expansion of other genes along with members of the Y-chromosome C haplogroup.

"Mongoloids can't have evolved in Beringia".

I have come to the same conclusion. My vote would certainly place them further south, perhaps somewhere on the Central Asian steppes. I'm prepared to concede, so as to avoid a prolonged argument, that it may have just been at the eastern end.

Epigenetic traits (such as Sinodonty) that have nothing to do with adaptational advantages make Dienekes's proposal unlikely.

The more likely scenario is two populations deriving from the same mtDNA lineages with divergent morphology. This scenraio must be true for the issue to be problematic in the first place, that "Mongoloids" of both East Eurasia and the Americas, paleo-Americans, and Ainu share the same mtDNA pool.

To say that these people have the same mtDNA but different morphology, and that the morphology later spread and that's why the same lineages have different morpholoogy is redundant, circular, and unnecessary.

If Mongoloid traits were selected independantly in 2 populations, then they would have to have been because of similar selection pressures.

I can only think of one possible scenario, accounting for some traits, that would be relevant, namely hunting with bow and arrow - as I'd imagine that this put a premium on binocular vision, so having a flatter face and particularly low bridged nose might have been very important??

It's strange that no one has addressed the fact that the development of the epicanthus is also observed among African populations, particularly Capoids and Nilotids. Is the etiology of the African epicanthus different from that of the Mongoloid epicanthus?

"To say that these people have the same mtDNA but different morphology, and that the morphology later spread and that's why the same lineages have different morpholoogy is redundant, circular, and unnecessary".

Several things wrong with that reasoning. First off, mtDNA has nothing to do with morpholgy. Secondly, Mogoloid-looking people don't all share the same mtDNA. Or Y-chromosome.

Onur. For some reason I'm having the same problem at remotecentral, and with your address. If you can see an obvious mistake in the address you provided post again. Or get in touch with me at terrytoohill@yahoo.com and I can send you the original diagram and essay.

Linguistic evidence suggests that Amerindians result from at least two, and probably more, migrations across the Bering Strait. These different migrations came from the same gene pool in northeastern Asia and would thus appear to be more or less the same genetically. But they 'sampled' the same gene pool at different moments in time.

Earlier migrants would thus tend to be more archaic in their physical appearance. Later migrants would tend to be more 'derived' (more physically similar to current populations in northeast Asia).

"Is the etiology of the African epicanthus different from that of the Mongoloid epicanthus?"

Evidently so. However the environmental cause is probably much the same.

"Mongoloids may have come to be what they are just because they chose to be what they are".

Not as simple as that. As in the case of African groups with similar characteristics the epicanthic eye fold is presumed to be an adaptation to glare from sunlight, basically through living in a semi-desert, or perhaps in this case icy, environment. Several other adaptations suggest that the Mongoloid type developed in very open, cold, glary conditions, possibly at high altitude. They have very little facial (or body, presumably genetically connected) hair. A frosted beard would be a huge disadvantage. And their skin has a concentration of keratin, very effective at reflecting intense light, rather than melanin. So they probably didn't just choose 'to be what they are', the environment pushed them.

Terry: it seems to me that Tim decided recently to detach your series into a separate blog (check his profile). Nevertheless this other blog is only accessible with invitation (surely an error). I'll tell him about this when I see him around.

...

As for the Mongoloid type as we know it, I think that it was just one of many interacting variants that popped up at the colonization of SE and East Asia, gradually becoming more and more dominant for whatever reasons.

There are a lot of people in Eastern Asia and Native America that do not have a well defined Mongoloid aspect. This is very clear amon Native Americans (varying a lot between populations and individuals but with many often showing non-Mongoloid traits such as lack of full epicanthic fold, very prominent noses or even curled hair - some even look vaguely Caucasoid, I'd say). Such variation is also found in East Asia, notably in SE Asia, which may have preserved better the original variability, together with isolate groups such as Ainus or others.

I do not think that the Mongoloid type is primarily product of selection (unless it's sociological selection) but of founder effects and drift. Also it can hardly be associated with any autsomal DNA, as these only represent a tiny fraction of all ancestry for whichever individual. It is probably much better correlated with autosomal DNA instead.

As much as I know, there is no evidence of founder effects and drifts in the evolution of today's Mongoloid race. Maybe first Mongoloid traits appeared in Africa as a result of drift, but I think their coming into dominance in East Asia cannot be explained with drifts and founder effects based on our knowledge about modern and ancient DNA. Autosomal DNA may be carrying some clues about such drifts, but I don't think drifts can alone explain such a drastic change in the morphology of East Asians and the related Amerindians in such a short time. Your model may work for the sparsely populated East Siberia, but, for instance, how about South East Asia, which was colonized much before?

Terry,

Where is the evidence that shows that the Mongoloid traits developed and spread as a result of extreme environments? And I can ask the previous question to you as well, albeit in a different way: How come they became dominant in SE Asia, where climate is in sharp contrast with East Siberia? Is there any genetic evidence that supports your north-to-south immigration scenario?

Onur: no idea if the traits were aleady existent in Africa or not: it was not my point.

Every pair of syblings is different, that difference is randomly generated in the reproductive process each generation. If I and my brother would be the sole founders (a very unreal case, I know) of two populations, these would end up being "racially" different based on what makes me and my bro different from each other (height, eye, skin and hair color, robustness, etc.)

That is how racialization happened: by founder effect and then also by homogeneization within intensely interacting populations. That's why we tend to thing of Tropical Africans as a single "race" even if their genetic variability is much greater than that of all other humans together: because they have homogeneized their traits by ilennary interaction across the continent.

Exactly the same happened in other regions of the world, Eastern Asia in the case dealt with here: when proto-Amerindians crossed Beringia the process of homogeneization towards modern "Mongoloid" type was still very much incomplete and hence hey brought with them to America that type (more or less) but also other traits that became dominant here or there on random genetic incidents.

Of course, you cannot discard some sociological selection: tall people are generally somewhat favored by most societies and also people with other traits that are subjectively considered "better" or "akin" or even just "beautiful" might have some slight advantage in the long run. This is very difficult to discard but is also, because of the complex and variable subjectivity involved, impossible to take apart from mere randomness.

Maju, as I've explained to you many times, SE Asians and often East Asians are not fully diagnosable as "Mongoloid", unlike Siberians, NE Asians, and Native Americans .

This is because the word "Mongoloid" only has any meaning when it is defined and tested with a set of criteria in physical anthropology (cranio-skeletal epigenetic traits and metrics). Even in terms of genetics, SE Asians have a heavy "negrito" mtDNA make-up.

Because of this foundational misunderstanding, all of your subsequent theories are flawed. This is the same problem with your Y-chromosome and mtDNA lineage theories.

Maju (...), SE Asians and often East Asians are not fully diagnosable as "Mongoloid", unlike Siberians, NE Asians, and Native Americans.

I don't see why Andeans would be more "Mongoloid" than, say, Thais. Thaksin is certainly much more standard "Mongoloid" than Evo and that comparison can certainly be extended to other SE Asian and American peoples. Tagalogs are more clearly "Mongoloid" than Mayans, etc.

This is because the word "Mongoloid" only has any meaning when it is defined and tested with a set of criteria in physical anthropology (cranio-skeletal epigenetic traits and metrics).

Apart of your silly craniometrical stuff, that I won't dispute, you need a short flat nose, marked epicanthic fold and normally straight hair. If you have no epicanthic fold, a very very prominent nose and/or curly hair and beard, then you are not "typically Mongoloid". This is what you find among many Amerindians (and are native traits).

Why? Certainly not admixture with Negritos in America... but just admixture of pre-Mongoloid and non-Mongoloid types (such as Ainu, for example) through the transit to Beringia, in Beringia and in America itself. Today's Beringians are not representative physiometrically of what existed there some 20 thousand years ago. Amerindians brought that variability with them and it was in East Asia back then.

Some people think of anthromoterical types (the so-called races) like if each had a unique Adam and an Eve founder couple. That is not correct. Ancestry is always a much more complex matter, even among relatively isolated and inbred populations.

For you, Ren, the "Adam and Eve" of "Mongoloids" were in NE Asia for some reason. But in my opinion the first carriers of such traits were in SE Asia instead, just that there they were not so dominant. In fact they were not yet dominant when people advanced through the coasts of East Asia to the North yet. And they were not dominant when they reached Beringia and continued away southwards towards Chile. Certain pre-existent Mongoloid traits may have been enhanced among subarctic peoples because of climate but that's all.

Racialization is a process and it is always an incomplete one. Because there's always too much variability dancing around for whatever standard to be universally true.

Well his paternal ancestry is Hakka (southern Chinese - SE Asian anyhow), his other half is pure Thai.

Anyhow, take any other, like Ang Suu Kii or Pol Pot. They all look pretty much "Mongoloid" to me.

And the variability of SE Asia, that does exist, does not show any particular Negrito tendency as far as I can see, but rather towards generalistic Eurasian traits, which were surely more important in the past.

You are selectively picking Native Americans and their alleged "Mongoloid" traits. If you just look at Inuits, then you do have a very good archatypically "Mongoloid" population, but that is hardly true for most other NAs.

...

Also, in the same line, it's worth mentioning surely what Kambiz posted at his blog: that the sample is too local and reduced to draw any significative conclusions.

"Where is the evidence to justify this assumption that various African, Asian, and American populations have developed epicanthic folds independently?"

I knicked that piece of information from a Cavalli-Sforza book. He claimed the Khoi-San and Asian eye folds were different, as I think you would agree if you look at photographs.

"As for the Mongoloid type as we know it, I think that it was just one of many interacting variants that popped up at the colonization of SE and East Asia, gradually becoming more and more dominant for whatever reasons".

That's not what the evidence shows. Early modern humans in SE Asia were similar to today's New Guinea/Papuan people. The Asian phenotype first appears in the region no more than 10,000 years ago, and possibly more recently still. The rice-cultivating people then came to dominate SE Asia.

"Such variation is also found in East Asia, notably in SE Asia, which may have preserved better the original variability".

In the case of SE Asia more likely remnant earlier survivals. The people of East Timor in in fact still look somewhat like an earlier hybrid population may have. Parts of coastal East Asia may preserve remnant populations too, e.g. Ainu.

"I do not think that the Mongoloid type is primarily product of selection (unless it's sociological selection) but of founder effects and drift".

Funny how most of us are instantly prepared to accept that the physical appearance of virtually every other species is a product of environmental selection, but we bend over backwards to deny it as a factor in the human species' physical appearance. Why the difference?

"Where is the evidence that shows that the Mongoloid traits developed and spread as a result of extreme environments?"

That information came largely from a Peter Bellwood book from 1978, so the idea has been around for a long time. However, as I noted above, we seem very reluctant to attribute an environmental effect to human physical appearance, the main exception being the dark skin of tropical populations.

"How come they became dominant in SE Asia, where climate is in sharp contrast with East Siberia?"

Archeological evidence. The genetic evidence can be interpreted as either northerly or southerly migration. But with today's overwhelming belief in a single expansion of modern humans along the South Asian coastline the only acceptable interpretation of the genetic evidence is for a northward migration.

"But in my opinion the first carriers of such traits were in SE Asia instead, just that there they were not so dominant".

Maju, of course Aung San Suu Kyi looks more East Asian than an Andean. The Burmese migrated to the Myanmar region in historical times from what is now China. But so what? Ethiopians look more like Yemenites then they look Saudi. How does that prove Ethiopians are more SW Asian than Saudis?

As I said, you keep confusing "East Asian" with "Mongoloid", and the result is logically disjointed arguments that make no point.

terryt, agriculture and "Mongoloid" skeletal types start showing up around 3,500 years ago in SE Asia.

"I knicked that piece of information from a Cavalli-Sforza book. He claimed the Khoi-San and Asian eye folds were different, as I think you would agree if you look at photographs."

That's interesting. Is there any heritability study or the like that has examined how the epicanthus of some Africans and the supposedly etiologically distinct epicanthus of Mongoloids might interact when interbreeding has occurred? More importantly, have the causative genes been identified?

(The three above should have a mix of Khoi and Dutch ancestry, AKA "Griqua")

http://www.safarilands.org/images/uploads/ee_images/185x220/hadza-002.jpg(This photo has been labeled as "Hadza," but don't you think that this woman and child look pretty similar to Khoisans?)

Maju,

It seems that you think craniometric and osteological data are "silly." How do you think the term "Mongoloid" has been defined in the first place? If you have such disdain for osteology, I suggest that you quit using the term "Mongoloid" altogether.

Early modern humans in SE Asia were similar to today's New Guinea/Papuan people. The Asian phenotype first appears in the region no more than 10,000 years ago, and possibly more recently still. The rice-cultivating people then came to dominate SE Asia.

What about the Liujiang skull? I'm rather with the conservative datations of c. 68 kya if anything but for someone like you who loves to explore the most unlikely possibilities, the extremist claim is of 150 kya.

One problem we face in most of Asia is lack of a good archaeological record and certainly very few human remains before Neolithic. Even if Liujiang is only 30-20 kya (early estimate based in comparsion with Japanese remains) that would make him/her older than the earliest Americans.

Now I'd like you to document the alleged "Papuan" SE Asians in the limited archaeological record of SE Asia. Thanks in advance.

The people of East Timor in in fact still look somewhat like an earlier hybrid population may have...

Well, I'd rather look to mainland SE Asia, even Sundaland if you wish but Wallacea is kinda extremist, don't you think?

Modern Negritos, AFAIK, live only south of the Kraa isthmus (and in Philippines), not in mainland SE Asia.

Funny how most of us are instantly prepared to accept that the physical appearance of virtually every other species is a product of environmental selection, but we bend over backwards to deny it as a factor in the human species' physical appearance. Why the difference?.

I am not prepared to agree with fitness selection being the only or even the main factor in most elements of appearence of any species. Would it be that way all species would be identical and would have converged towards the same narrow range of phenotypes. Obviously random innovation (Chaos in action) is creating diversity: many different solutions for similar problems, often very capricious ones.

Remember that the first actor of evolution is mere randomness, selection can only act (unless Lamarck was right) on what already exists. Otherwise we would surely have 4, maybe 6 or 8, arms because it is so obviously more practical...

But we have evolved from quadrupedes, not octopuses. And evolution did the best it could with that.

Now wether we have curly or straight hair, black or yellow or red... it is probably trivial in terms of fitness (or at least nearly so).

Extensive immigration.

Documented how? Just a far fetched speculation, IMO.

Archeological evidence.

Which one?

The genetic evidence can be interpreted as either northerly or southerly migration.

Ahem. The genetic diversity is for nearly all clades highest in SE Asia or at most southern China. Maybe Japan is an exception but seems to have been populated since long ago.

The more and more this issue is researched the south seems more clearly at the origin of most lineages, if not all.

The Burmese migrated to the Myanmar region in historical times from what is now China.

And they made a genocide of the original inhabitants? Has anyone even bothered researching how the original people of Myanmar looked like before that historical "migration" (conquest).

you keep confusing "East Asian" with "Mongoloid"

They are the same, excepting the oddballs like Ainu. It's like "West Eurasian" and "Caucasoid". the only difference is that one is a mere geographical term and the other the anthroposomething approach to the reality of that roughly homogenous human reality. It is interaction what makes race by homogeneizing the phenotypes.

It seems that you think craniometric and osteological data are "silly." How do you think the term "Mongoloid" has been defined in the first place?.

Craniometry can only reach so far and anyhow it is abstruse and hard to use in daily terms. You seldom see a profile pic, for instance, what is crucial to determine some of the main craniometrical traits. People in fact does notice the "racial" difference based in other traits such as the presence or absence of epicanthic fold. Even it seems some Bushmen took some Vietnamese (or was that Chinese?) as fellow members of their nation on first sight. So it's not like non-craniometric data like the epicanthic fold, the prominence of the nose or the texture of hair are trivial - just that these cannot be found anywhere in skulls. But they are equally defined by genetics, maybe even more than some skull traits.

Still the paper does not study a sufficiently large sample: it may be like observing penguins and concluding that all birds swim.

Maju, "West Eurasian" is rather a genetic grouping that would include various groups in Europe that survive into the Neolithic with morphologically "un-Caucasoid" faces. The two terms are quite different.

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Anyway..I'm surprised to find that 13% of Spaniards have concave noses and are thus Mongoloids.

"The nasal profiles of some 120.000 Spaniards are convex in 15 per cent of cases, straight in 72 per cent, and concave in 13 per cent. In Arabia and North Africa east of Morocco, the commonest profile form is usually convex, and concaves are very rare."http://www.geocities.com/refuting_kemp/coon_spain.html

Maju, "West Eurasian" is rather a genetic grouping that would include various groups in Europe that survive into the Neolithic with morphologically "un-Caucasoid" faces. The two terms are quite different.

Like?

Anyway..I'm surprised to find that 13% of Spaniards have concave noses and are thus Mongoloids.

Hey, I do intuitively agree that concave noses are Oriental (Mongolid-related if you wish) and that they massively increase towards Eastern Europe. I'm glad that for a change we are in some agreement, Ren.

Still, I'd say that prominent concave noses are very much un-Mongoloid, as much as the prominent convex noses of Andeans (and so many other Native Americans).

This brings us to the interesting issue of what is a "race": a vague trend approaching an archetype or just those that are almost identical to the archetype. In the first case, races soverlap and are very much clinal, in the second cases, races are just a handful of specimens and the vast majority of the people are non-racial (or maybe each one his/her own different race).

But well, I'd like you to explain me how southern Liujiang and northern Zhoukoudien specimens (I fear there's not much more to study in mainland East Asia) approach better or worse the Mongoloid craniometric archetype.

I know the result: Zhoukudian is not Mongoloid or just very vaguely so (eyebrows) while Liujiang is almost a perfect modern fit.

Now, after doing this excercise of archaeo-anthropometry, please try to ratify yourself in the old rotten hypothesis that Mongoloids "invaded" the south from the north and not exactly the opposite. I know you will, but have no idea how. Please describe the process using an old semi-scientific tehnique called introspection, where the writer tries tod escribe his psychological process as objectively as he/she can. This should be a very interesing excersise and may even prevent you from falling in the same trap again (who knows?).

I'm talking about SE Asia here, not mainland China. As Ren said, "agriculture and 'Mongoloid' skeletal types start showing up around 3,500 years ago in SE Asia", although I understand it is more like 3,500 BC, i.e. 5,500 years ago. Until then what was going on further north is irelevant for SE Asia.

"Now I'd like you to document the alleged 'Papuan' SE Asians in the limited archaeological record of SE Asia. Thanks in advance".

It was certainly widely accepted from the 1960s on, so most of the evidence is in books from around then and ancient articles rather than modern ones on the Internet, but I'll have a look.

"Modern Negritos, AFAIK, live only south of the Kraa isthmus (and in Philippines), not in mainland SE Asia".

And why would they now be confined to just those regions? Isolated by incoming East Asians perhaps? And why do the pre-European inhabitants of New Guinea, Australia and Melanesia look different from those in SE Asia?

"Would it be that way all species would be identical and would have converged towards the same narrow range of phenotypes".

Not unless they were all from the same population and subject to exactly the same selection pressure.

"The genetic diversity is for nearly all clades highest in SE Asia or at most southern China".

You have many times pointed out that highest genetic diversity does not necessarily indicate place of origin. And I agree. Less genetic diversity casn be a product of bottleneck, founder effect or selection.

"Maybe Japan is an exception but seems to have been populated since long ago".

So where from?

"They are the same, excepting the oddballs like Ainu".

Not really. Mongolians look different (more extremely Mongoloid?) than do Chinese for example. SE Asians look even less 'Mongoloid'.

"don't you think that this woman and child look pretty similar to Khoisans?"

Yes. But they could well be Hadza. I've remembered that the main difference between East Asian and Khoi-San eyefolds is that the Mongolian fold is on the inside of the eye and the African one on the outside. Tends to hold up in the examples you've linked to.

"These comparisons demonstrate that the Moh Khiew specimen resembles the Late Pleistocene series from Coobool Creek, Australia in both cranial and dental measurements. These results suggest that the Moh Khiew skeleton, as well as other fossil remains from the Tabon, Niah and Gua Gunung sites, represents a member of the Sundaland population during the Late Pleistocene, who may share common ancestry with the present-day Australian Aborigines and Melanesians".

Liujiang county is part of the Guangxi Zhuang autonomous region of China, just north of Vietnam and Laos. Using modern political borders is of no help here, moreso whe there is widespread consensus that Southern China is more akin anthropologically to SE Asia than to Northern China.

In any case Guangxi Zhuang is much closer to, say, Bangkok than your arbitrary Timorese example.

As Ren said, "agriculture and 'Mongoloid' skeletal types start showing up around 3,500 years ago in SE Asia"...

The Liujiang skull proves him wrong.

And why would they now be confined to just those regions? Isolated by incoming East Asians perhaps?.

Incoming SE Asians in fact: Austronesian expansion. But that is not what pushed them, AFAIK, south of Kraa Isthmus but what pushed them to marginal areas within the Malay (Austronesian) region.

And why do the pre-European inhabitants of New Guinea, Australia and Melanesia look different from those in SE Asia?.

Probably because these are two distinct regions with little contact with each other, much like Papuans and Australian Aborigines also look pretty different.

Not unless they were all from the same population and subject to exactly the same selection pressure.

Ok, so we agree that evolution works with what it already has: it can't make a lion out of a zebra, right?

You have many times pointed out that highest genetic diversity does not necessarily indicate place of origin.

And I have many times insisted as well that you need a very good explanation to counter the argument of highest genetic diversity.

Anyhow, you tend to confuse diversity in general with diversity within a clade and these two with diversity at some genealogical level within the clade. These are three distinct phenomenons in fact and cannot be put under a single simplistic umprella term like "highest diversity".

The devil is in the detail. Pay attention to details, please.

So where from?.

SE Asia, via the coast. Alternatively maybe you prefer an explanation that includes a UFO from Uranus but personally I think it's rather far fetched.

Maju. Here are some comments regarding the Hoabinhian (p. 86). The people are regarded as being Australo-Melanesian, not Mongoloid.

Hold on. It reads: "... many skulls from Hoabinian sites have been accorded a degree of Australo-Melanesian affinity ..."

This is extremely ambiguous, notably considering the typical riff-raffs regarding such classifications.

The eponym province of Hòa Bình, in North Vietnam, is certainly not far from Liujiang in any case, so I would be rather surprised if these claims could be confirmed after serious research. It would mean that the arbitrary modern political border was also an ancient ecological one, what is most dubious, IMO.

And this one says:

"These comparisons demonstrate that the Moh Khiew specimen resembles the Late Pleistocene series from Coobool Creek, Australia in both cranial and dental measurements. These results suggest that the Moh Khiew skeleton, as well as other fossil remains from the Tabon, Niah and Gua Gunung sites, represents a member of the Sundaland population during the Late Pleistocene, who may share common ancestry with the present-day Australian Aborigines and Melanesians".

This is more clear maybe but still I find difficult to see how these remains can be both similar to Australian Aborigines and Melanesians. You have long argued that these two populations are clearly distinct in fact (something I agree more and more, and make further distinctions between Island Melanesians and Papuans and then Negritos as well). I must remind you that Ainus were in the past considered "Australoid" in spite of being quite different.

I have already argued that SE Asia surely preserved higher typological diversity, so finding "some affinities" with other groups does not surprise me the least. I look at Zhokoudian skulls and I also find them vaguely "Australoid" if you push me a bit. This is just because they are archaic Eurasians.

You have much of the same problem in a much better researched area as is Europe: in the course of milennia you find different individuals that can be argued to make up different types (Aurignacoid, Cromagnoid and modern/Magdalenian basically). For some this evolution represent population replacements, even if there is no obvious source nor cultural vehicle for the replacing peoples, while for others it is mostly in situ evolution, phenotypic drift.

I am, mostly, with the second explanation but cannot fully discard some influence from random migrants. And I think that the same applies to Eastern Eurasia.

This looks like another photograph of the same Datoga woman as above:http://image46.webshots.com/47/4/49/26/375544926ACdYjy_ph.jpg

Fully formed eyefolds seem to be common among the Khoisan groups (and maybe also among the Sandawe and Hadza, although I have not seen many of these folks in photographs or otherwise) in Africa, but this trait is at least moderately expressed among many Nilotic folks in Sudan and elsewhere in East Africa. I think it is unlikely that this trait has been introduced into East African populations via gene flow from the Khoisan populations of Southern Africa, so the trait must have already existed in an ancestral population that has contributed genetically both to the present Khoisan peoples and to the present Nilotic peoples. However, I suppose it should also be possible that the trait has been introduced into the Southern African Khoisan via East Africa together with the initial spread of pastoralism in these parts of Africa, and it has subsequently been diluted in East Africa.

I have been reading some more on Hoabinian and East/SE Asian prehistory and it seems that this mainland SE Asian culture (with offshots in China and other places) may have been central in the developements after the LGM in the whole region. Some even argue it was at the origin of East Asian Neolithic and were the first bronze casters ever.

And, btw, Ebizur's digression on epicanthic fold being maybe derived from an ancestral African genetic pool makes sense, after all this trait is found not just in East Asia but also (normally in partial incomplete form) in West Eurasia and, of course, among many Africans.

terryt, debating with Maju is a waste of your resources, because it often is about irrelevant issues. Take your protracted debate with him about Liujiang.

As far as I know, there is nothing diagnosably "Mongoloid" about Liujiang. The only diagnostic analysis, besides the limited glance by Wu and Suzuki, is the detailed analysis by Brown, which place the cranium closer to Austro-Melanesian forms. It's size is pygmy.

References to it as "Mongoloid" has been arbitrarily passed down from Mao-era Chinese anthropologists into Western multi-regionalists' mouths (such as Wolpoff and Stringer). By their reasoning all humans discovered in China have indigenous-non-African "Mongoloid" traits, going back to Asian Homo erectus.

The facial morphology of Liujiang is actually closer to Australo-Melanesians, and for that matter UP Europeans, Africans, Ainu, etc.

For a more detailed description of Liujiang, I might make a post on my blog.

"It would mean that the arbitrary modern political border was also an ancient ecological one, what is most dubious, IMO".

Many modern political borders coincide with ecological borders. That's where they derive from. Is the border between Spain and France 'arbitrary'? Italy and France? Nepal and Tibet? The border between Vietnam and Southern China is hardly arbitrary.

"Incoming SE Asians in fact".

You would hardly use any SE Asians as an example of mongoloid phenotype. The phenotype reaches it's extreme way to the north.

Ebizur. Thanks for those links.

"As far as I know, there is nothing diagnosably 'Mongoloid' about Liujiang".

Maju. There's not much all that surprising to me in those references. After all I have been following developments in understanding Polynesian origins, including genetic developments, for more than thirty years.

For a start the article emphasises that it deals with the period before the Austronesian expansion, which many people associate with the arrival of the Mongoloid phenotype in SE Asia. E is obviously indigenous, and surely no-one (except you) doubts that there has been considerable human movement backwards and forwards since the time some Australopithecus/Homo species first left Africa. So the conclusions in the article are hardly earth-shattering.

The second link stresses the difference between the pebble, or Hoabinhian, culture of the south and the microlithic of North China. It has long been understood that the expansion into the Pacific from Taiwan/Philippines was preceded by the arrival of a microlithic culture. The only disagreement is whether it came from the north or from the west (india). My vote has tended to favour the north although obviously you'd favour India.

The third link:

"Material excavated and analyzed during the past five years suggests that men were cultivating plants there, making pottery, and casting bronze implements as early as anywhere on earth".

I actually agree with virtually everything the author has written in the section, "Puzzle Begins to Fit Together". But I remember you arguing vehemently against me when I suggested exactly those points(well, to be honest I didn't include bronze). So when Ren says, "debating with Maju is a waste of your resources" I'm very inclined to agree with him.

Absolutely: it divides two ethnicities and, fyi, in the Basque part at least it does not even follow the mountains for the most part, but a minor river and other capricious features.

You could choose other examples as the broder between Moldova and Ukraine or that between Poland and any of its neighbours or soo many others (Belgium, Switzerland, Austria, Hungary...), like the border between the USA and Canada: a mere line on a map. Modern political borders are in most cases arbitrary lines drawn for mere historical accident and political convenience, often ignoring the inhabitants.

Nepal and Tibet?.

There is no such thing as "Tibet" if we talk political borders. Tibet is like the Basque Country or Palestine: a stateless nation.

But anyhow, you picked the highest mountain range of the World, hardly comparable with what we are discussing here. Why don't you study the border between Nepal and India instead? That is a good example of a totally accidental border with no ethnic or physical barrier. Most political borders of Earth today are that way.

The border between Vietnam and Southern China is hardly arbitrary.

It is. It's a modern convention. It does follow some hills and has certain historical consolidation (specially if you compare with the borders of the USA or Congo) but that's about it.

You would hardly use any SE Asians as an example of mongoloid phenotype. The phenotype reaches it's extreme way to the north.

That is only because it was arbitrarily defined that way. If Caucasoids would have described using a Swedish skull instead of a Daghestani one that would be also the case in West Eurasia. But if they would have been described using a Moroccan skull, it would be different too. And so on.

"These results only account for 15% of ISEA mtDNA lineages".

Again a good example of your chosy tendentious self-satisfying style of discussion. Immediately after that sentence they explain that it is also probably the case for many other lineages, just that study is focused on Y-DNA E.

The second link stresses the difference between the pebble, or Hoabinhian, culture of the south and the microlithic of North China.

With the flake industries of North China, Indonesia and Sahul, if I'm correct.

It has long been understood that the expansion into the Pacific from Taiwan/Philippines was preceded by the arrival of a microlithic culture. The only disagreement is whether it came from the north or from the west (india). My vote has tended to favour the north although obviously you'd favour India.

IMO microlithism is a industrial trend, not a culture. Whoever thinks that microlithism means population migrations and even total replacements, should just scrap whatever happened before and should start considering why people is so different if after all we just diverged some 10 kya. (Sarcasm intended). Forget about OOA, all began with microlithism and all what happened before was just rolled over (sarcasm intended again).

I actually agree with virtually everything the author has written in the section...

He basically states that Hoabinian is at the origin of agriculture, at least in East Asia. So I find surprising youd agree with that, as it contradicts everything you're claiming elsewhere.

But I remember you arguing vehemently against me when I suggested exactly those points(well, to be honest I didn't include bronze).

Well, I'd suggest you to join his forum and enjoy his style instead.

I cannot remember what discussion you mean here anyhow but I understand I am entitled to change opinion, right? Though most probably it's just you misinterpretating me.

I quote: "There is nothing particularly East Asian about the facial skeleton of Liujiang".

Ok. Let's assume it's the case (others think otherwise but wahtever), then where and when did the modern "Mongoloid" phenotype appeared? What does the archaeological record say?

"Ok. Let's assume it's the case (others think otherwise but wahtever), then where and when did the modern "Mongoloid" phenotype appeared? What does the archaeological record say?"

Human remains that have been diagnosed as Mongoloid and that are associated with a well-described archaeological culture first appear in northwestern/north-central China (e.g. http://en.wikipedia.org/wiki/Baoji) in the Neolithic of about 7000 years BP. This coincides, both geographically and temporally, with the incipient Yangshao culture (AKA "Yellow River Neolithic"), which many researchers have associated (on what grounds, I do not know) with either the proto-Han Chinese ethnic group or the proto-Sino-Tibetan language family.

However, earlier diagnosably Mongoloid remains have been found in isolated sites in America and Siberia, which might suggest that the appearance of Mongoloid morphology in Neolithic north-central/northwestern China has been caused by the migration of a population from a source in Siberia (or America, if you want to be even more speculative).

"He basically states that Hoabinian is at the origin of agriculture, at least in East Asia. So I find surprising youd agree with that, as it contradicts everything you're claiming elsewhere".

I'm afraid that is exactly what I suggested in the series of essays at remotecentral I called "Pacific Population", under the section 'Hoabinhian', and in the essay "The Last Point", in the section 'Pottery'. And in "Into Australia", 'Kow Swamp', I mention the 20,000 year date for the introduction of ground-edged stone tools to that continent. In fact what got you so worked up to start with was my essay "MtEve", 'The Branches', where I suggested there had been an expansion from around Wallace's Line, a position very close to that of your third link.

"Human remains that have been diagnosed as Mongoloid ... first appear in northwestern/north-central China". And "earlier diagnosably Mongoloid remains have been found in isolated sites in America and Siberia".

Those comments actually fit very well the idea that the Mongoloid phenotype originated in the high country of Northwest China, my original position. And that's where we find the most extreme examples of the phenotype today. And that is totally independent of any claim 'That is only because it was arbitrarily defined that way'. It just is so, however you like to define the Mongoloid phenotype.

Some of you may find this paper interesting: "A spatial analysis of genetic structure of human populations in China reveals distinct difference between maternal and paternal lineages".

From the abstract:

"In this study, we systematically explored the spatial genetic structure and the boundary of north–south division of human populations using mtDNA data in 91 populations and Y-chromosome data in 143 populations. Our results highlight a distinct difference between spatial genetic structures of maternal and paternal lineages".

http://www.nature.com/ejhg/journal/v16/n6/full/5201998a.html

From the paper:

"In the past two millennia, there have been major population movements toward the south in China.8, 29, 30, 31, 32 In particular, Wen et al7 showed that such movements were sex-biased and mostly involving much more males than the females. These sex-biased gene flows, therefore, constituted a great deal of impact on the genetic structures of the extant populations and led to the differential structures of the populations between the maternal and paternal lineages as seen in this study".

Of course this is after any Hoabinhian movement. So there has been movement north and south, and all around, in Eastern Eurasia since humans first arrived there.

I think most of us agree that the phenotype is centred on Central, Northern and East Asia, and its influence tails off towards its geographic extremities: America, the Russian steppes and in the wider Pacific. Polynesians, for example, display some influence of the Mongoloid phenotype but it is there mixed with another phenotype, the Melanesian. So where did the Mongoloid phenotype originate?

We should start with the assumption that the absence of mtDNA A in the South American sample (the subject of this post) is actual and significant. Onur mentioned that "The extent of haplogroup A is very limited among East Asians". But all groups with a proportion of the mtDNA A definitely have Mongoloid features, usually strikingly so. And mtDNA A is certainly well represented in Eskimos, the most Mongoloid-looking Native Americans. In fact mtDNA A basically forms a cline within America from north to south. The phenotype is not just associated with mtDNA A's presence in Asia though. If the phenotype actually originated with mtDNA A it has certainly spread to other mtDNA haplogroups.

What about Y-haps? Y-hap C3 is certainly associated with the Mongoloid phenotype through Central Eurasia, and may have been connected to its introduction to America. But in Japan its relative, C1, is usually accepted to be Ainu, not Mongoloid.

Anyway mtDNA A and Y-hap C3 barely enter SE Asia, so clearly the Mongoloid phenotype cannot be associated only with these haplogroups.

The authors of the link I provided claim male gene flow southward in China, so the southern expansion of the phenotype must be linked to a Y-hap. Really the only credible candidate is some member, or members, of the O Y-hap group. In the far east Y-haps N and O are both closely associated with the phenotype. Perhaps they too originated near Central Asia. Y-haps C3, N and O certainly share Central Asia today. Y-hap Os may therefore have carried the Mongoloid phenotype south as far as SE Asia, and even a little way out into the Pacific.

Back to mtDNA. Haplogroup B is very interesting. In the Pacific it is associated with the Mongoloid element of the Polynesian ancestry. And mtDNA B is common in America, especially along the western, or Pacific, side. But if Dienekes' original post is correct the haplogroup is not there associated with the Mongoloid phenotype.

We therefore have the interesting situation that in Polynesia the Mongoloid part of the mix has probably come in with a mtDNA haplogroup not at all associated with that phenotype in America (B). And a Y-hap associated with the Mongoloid phenotype in America is, in Polynesia, associated with the New Guinea/Melanesian part of the ancestry (C2).

We can draw the conclusion that haplogroups are not necessarily closely associated with genes for particular phenotype. Each individual gene is independent to a surprising extent.

I think the Mongoloid and Amerind phenotypes both originated in Siberia as adaptations to extreme cold, but the Amerinds left this climate zone sooner and so did not move as far in the direction of adaptation to cold.In America the Amerinds of the western part of the continents usually had more nearly Mongoloid features than those to their eastern. I think the cause was a combination of two things: (1) the westerners arrive later (and so left the cold ancestral homeland later) and (2) the western regions have many highlands, some of which are so high that they have a signifcantly colder climate than the east.Regarding mtDNA haplotypes, I think that the original phenotypes were as follows: D--Negritoid, C--Australoid, and B and A--Caucasoid on the way to Mongoloid (via Amerind)--which last I would also say about the Y haplotype Q.

"I think that the original phenotypes were as follows: D--Negritoid, C--Australoid, and B and A--Caucasoid on the way to Mongoloid".

I could perhaps be persuaded you might be correct regarding A and D. But there's not a hell of a lot of mtDNA C in Australia, or New Guinea. None to be exact, except perhaps for some modern Chinese. And B seems closely associated with Eastern Asia, perhaps originally SE Asia and so maybe not strictly Mongoloid, but certainly not Caucasoid.

Gregory: nonsense. C3 is associated with Mogoloids. The process of racialization cannot be simplified as you did: it's more a process of phenotype homogeneization in geographic areas than any essentialist anything.

Amerindians just migrated before the Mongoloid type or types were "finished" (does this process ever finish?), same as Ainus, Andamanese, etc. - but at a later stage.

B is descended from R, whose other descendents are mostly Caucasoid, so if B was not originally Caucasoid (and it may not be) its ancestors were.MtDNA C is not Australian, but, among Asians, it is strongest among the northern Tungus, and the strongest Y haplotype among them is C, which is strong in Australia. And the ancestor of C is M, which is strong among Negritoids and Veddoids, and the latter are usually counted as Australoid. As to C3, Maju, I said nothing about it, and it is a subtype of C.As to essentialism, I am philosophical what is sometimes called an 'essentialist', but in biology essentialists are concerned mainly with phenotype, and if the take account of genotype they assume it corresponds with phenotype--and that is not my view. Nor did I say anything that logically implied that. Did you think I did, Maju?As to your comment about Amerind leaving the area before the process of formation of Mongoloids is finished, that is just what I was saying--except I did not say that the process "finished".

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